The .SUBTITLE command allows you to specify a subtitle for a
    running head (see .HEADERS ON). When using the default .LAYOUT
    command, the subtitle appears on the second line of every page
    (except page 1) at the leftmost position on a line (character
    position 0), regardless of the left margin setting. The .NO
    SUBTITLE command cancels the .SUBTITLE command. (See also
    .AUTOSUBTITLE, .TITLE, .FIRST TITLE, and .LAYOUT.)

    Formats

      .SUBTITLE  [text]

      .NO SUBTITLE

    Abreviated formats

      .ST  [text]

      .NST

1  –  Parameter

 text

    The title of the running head you want to appear on the second
    line of the page.

2  –  Defaults

    o  If you do not enter either .SUBTITLE or .NO SUBTITLE, you get
       .NO SUBTITLE.

    o  If you enter the .SUBTITLE command without specifying subtitle
       text for it, you will get the effects of .AUTOSUBTITLE
       (provided you have not entered .NO AUTOSUBTITLE).

    o  If .AUTOSUBTITLE is in effect and if the text picked up from
       an applicable .HEADER LEVEL command is wider than the margins
       in effect when the subtitle is displayed, the subtitle is
       truncated and an ellipsis (...) is appended to the end of it.